Our Z4 has been tested at Texas Tech University’s National Wind Institute. Their wind cannon shot fifteen-pound two-by-fours simulating debris in a 250-mile-per-hour EF-5 tornado. Our shelter passed the test with an exceptional performance. Our tested shelter is available at our store so you can see for yourself how little damage an EF-5 tornado would cause to your shelter.

To ensure your family’s safety, we went another step further and had a wind engineer create a written wind evaluation. Quality verification involves having the shelters not only debris impact tested, but also a written structural wind engineer evaluation. The structural wind engineer evaluation is not the same as a stamped engineered drawing. Any engineer can stamp a drawing. Only an engineer specializing in wind engineering can provide a written structural third party evaluation.

Each shelter we produce is given an NSSA serial number and seal, and a certificate of installation. Your serial number is registered with the NSSA. When a tornado event occurs, NSSA teams inspect these shelters to verify that they performed as they should. Since our company was founded in 2003, we have never once had a shelter that did not perform as expected during a tornado.

Our safe rooms have been verified to comply with the NSSA/ICC 500 (2014), FEMA P-361 (2015), and IBC (2015) codes.

As an additional safety feature, our doors swing inward to reduce the chance you could be trapped inside the shelter by debris. (You can choose if you want the door to swing in to the right or left.) Even our vent covers, located on the door, are covered so flying debris cannot get inside the shelter.

The Z4 is the first safe room in America to have a seismic rating. It is currently being evaluated by engineers, and it was designed using the same technology that oil companies use to protect their employees from earthquakes. The official “shake test” will be performed in 2018.

Because of our door construction, the interior handle operates independently from the exterior handle. Once inside, a person can use the bolts to lock the door, and no one outside can get in. If someone outside attempts to lock you inside, the interior door handle will always open because of the internal bypass mechanism.

The Z4’s premium grade steel makes it virtually impenetrable from the outside by debris or intruders. Our internal door hinge design makes the door pry-resistant from an intruder who may try to crowbar their way in. This design also allows the door to safely open inward even if damaged. A former Navy Seal conducted a ballistics test on the safe room and the results concluded the Z4 is resistant to most common ammunition calibers. The tested steel shelter plate is on display in our showroom.

Many of our customers also use the Z4 as a walk-in vault. We offer a high security lock as an option, or customers can use a padlock of their choice on the door. It is a great way to protect valuables from an intruder.

FEMA has two standards for storm shelters: residential and commercial. Because much of our business involves commercial shelters for Fortune 500 companies around the nation, we go ahead and build all our residential shelters to the higher commercial shelter standards. This provides your family with the same level of protection that companies like Google, Microsoft, nuclear power plants, and even the U.S. Government give their employees.

To protect from tornados, our safe rooms must be bolted into reinforced concrete at least 4” thick. We often place our shelters in garages, basements, or on concrete pads in a backyard. We can also put the rooms in home interiors to act as a panic room, but without a concrete base it will not protect from a tornado. To ensure that installation meets this NSSA standard, we provide a FREE site inspection visit from a qualified member of our Stronghold team.

The price of your shelter will vary based on size, installation location, and your selected options. Within 75 miles of Springfield, MO, our price includes delivery and installation. Outside of 75 miles, we may need to add a mileage charge to cover travel expenses. We also offer a free site inspection and consultation to verify the installation location. For an exact quote, please call or email one of our Stronghold Sales Representatives at 417-725-0055 or 888-777-8171 or info@strongholdsaferooms.com .

Have Questions?

For help choosing the right gun safe or safe room for your family, or if you have any questions about our products, contact us through the link below or at 877-883-0733 and our friendly customer service representatives will be happy to help you.
Contact Us